BS4825-5 RJT Couplings Info

BS4825-5 RJT Couplings Info



BS4825-5 RJT Couplings info


The RJT (Ring Joint Type) hygienic couplings are the most commonly used connection type in the dairy, brewery and beverage industry in the UK. A special standard chapter has even been made for it, namely the BS4825 part 5 standard.


The RJT coupling is a robust connection type that is easy to assemble and disassemble with a corresponding hexagon wrench.


The sealing gasket is pressed by the liner into a perfectly fitting groove of the male part. The special shape of the liner ensures that the sealing gasket has little or no contact with the flowing medium. This can be a major advantage because the medium now only contacts stainless steel in the entire process system.
Because there is always a (minimal) small gap between the liner and male part, this coupling is not really suitable for CIP cleaning.


For parts of a process installation that are regularly disassembled for cleaning, an RJT coupling is often a good choice.

The parts that come into contact with the process medium (liner and male part) are made of 316 grade stainless steel by means of CNC machining. The nut is usually made in 304 grade stainless steel.

Like other hygienic fittings, the roughness of internal surface does not exceed Ra = 0.8 μm.







Facts about RJT hygienic couplings:


  • Extended name: Ring Joint Type coupling

  • For tube standards:

    • British Standard BS4825-4
    • International Standard ISO2037
  • Parts:

    • Liner

    • Nut

    • Sealing gasket

    • Male part

  • Diameter range:

    • 1”
    • 1 1/2”
    • 2”
    • 2 1/2”
    • 3”
    • 4”​​


  • Materials

    • Liner and male part: Stainless steel grade 316
    • Nut: Stainless steel grade 304


  • Materials sealing gaskets:

    • NBR
    • Nitrile Rubber
    • FPM
    • Fluorine Rubber
    • EPDM
    • Ethylene Propylene
    • Nitrile
    • Viton
    • PTFE
    • Silicone ​​
  • Temperature: -30°C / -22°F up to +120°C/ +248°F
  • Maximum allowable working pressure (for the coupling alone) is 15 bar.
  • Applications: In process systems that not often need to be disassembled.
  • Advantage: An almost gap-free passage in the coupling and a sealing gasket that hardly comes into contact with the flowing process medium.
  • Industries:
    • Dairy
    • Breweries
    • Cosmetics
    • Chemicals
    • Food and beverage
    • Pharmacy
    • Biotech



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